Governments have the right to print their own money and to decree: “We do not accept foreign currency.”
In the late 1400s, their Most Catholic Majesties, Ferdinand and Isabella, ruled the growing Spanish Empire. They sent brave explorers to the New World. A handful of men under Cortez overthrew the brutal Aztec Empire based on slavery, torture, and human sacrifice.
Pizarro did the same in Peru. Ships of gold and silver returned to Spain from the New World. Their Most Catholic Majesties and successors reduced Protestant apostasy and stopped Moslem invasion at Lepanto, in 1571. The “coin of the realm” was based on silver and gold.
In some places, paper replaced silver, gold, and other things.
Now, governments print money at the speed with which automation technology advances. In sound governments, Catholic Fundamentalism understands that the rate at which money is printed will reflect the increased amounts of goods and services provided ever more cheaply by automation.
That being said, a more important question arises. What is the coin of the realm beyond? What does The Kingdom of God use for money?
Faith and obedience are the coin of the realm beyond. Faith is like coinage. Obedience? It is like folding money. Obedience that leads to martyrdom is folding money of very, very large denominations.